You're out for a leisurely walk and a black cat runs across the sidewalk in front of you. It's Friday the 13th, so you stay home. In our society the number 13 is so feared, (and there's a name for it, triskaidekaphobia) that many airlines will not have a Row 13 on their airplanes, and hotels and buildings will not label a 13th floor.
Have you ever wondered if athletes carry a lucky charm or four-leaf clover in their pockets or lockers? There are many superstitions in our society, but no sector of society is more superstitious than the world of sports.